|We have five phases for each GPU, making the ICs from Infineon TDA21211 DR.MOS sites, supporting a peak current of 35 A and therefore use inducers 35A had to be at least enough not to touch before mosfetii the 35A. I do not have specifications for those inducers, but to give you an idea I can tell you that high quality inductors on Asus RE3 supports a peak current of 40 amps and are more than three times higher. We have very fragile Dr.Mos chips (currently available IC's Dr.Mos 50 amps) and not very efficient in energy conversion, and mini-inducers, which anyway would be made redundant more than 30A mosfet, a combination very-very poor, I never thought I'll ever see it on a motherboard of this caliber.|
He talks earlier, and I agree, that the minimum we would have liked to see would be a six phase VRM with 40A+ mosfets (maximum theoretical load: 240A). Instead we get a four phase VRM with 35A mosfets (maximum theoretical load: 140A).
The reference HD6990 uses a six phase VRM with each phase capable of 80A (maximum theoretical load: 480A).
Higher the current rating of the mosfets used in the phases, the more current is available to the GPUs. Current increases directly as clock speed. If the components are rated too low the GPU can draw too much power and cause the mosfet to fail. Additionally, more phases means cleaner power, which means easier overclocking.
Also, in case anyone brings up VI=P and argues that higher voltage means lower current, remember that in a switching power supply the forward voltage of the transistors remains constant, and that output voltage is determined by the inductor and the duty cycle of the transistors. Higher output voltage means a higher duty cycle of the switching transistors, means that that high current levels are sustained for longer.
Edited by Phaedrus2129 - 3/31/11 at 10:02am